Surface-coated cutting tool

Abstract

A coating layer including first sublayers and second sublayers alternately deposited. The first sublayers each has an average thickness in a range of 0.5 nm to 100.0 nm and has an average composition represented by (Al x Ti 1-x-y-z M y )B z N (M is at least one element selected from the group consisting of groups 4, 5, and 6 elements and lanthanoid elements in the periodic table, 0.100≤x≤0.640, 0.001≤y≤0.100, 0.060≤z≤0.400). The second sublayers each has an average thickness in a range of 0.5 nm to 100.0 nm and has an average composition represented by (Al p Cr 1-p )N (0.650≤p≤0.900). The coating layer includes a cutting edge ridge and a flank and has a B content, the B content at the cutting edge being at least 60% of the B content in an area at least 1 mm away from the cutting edge ridge toward the flank.

1 . A surface coated cutting tool comprising a substrate and coating layer on the substrate; wherein
 1. the coating layer has an average thickness in a range of 0.1 μm to 10.0 μm, the coating layer including first sublayers and second sublayers alternately deposited;   2. the first sublayers each has an average thickness in a range of 0.5 nm to 100.0 nm and has an average composition represented by the formula (Al x Ti 1-x-y-z M y )B z N (where M is at least one element selected from the group consisting of groups 4, 5, and 6 elements and lanthanoid elements in the periodic table, x is in a range of 0.100 to 0.640, y is in a range of 0.001 to 0.100, and z is in a range of 0.060 to 0.400);   3. the second sublayers each has an average thickness in a range of 0.5 nm to 100.0 nm and has an average composition represented by the formula: (Al p Cr 1-p )N (where p is in a range of 0.650 to 0.900); and   4. the coating layer includes a cutting edge ridge and a flank and has a B content, the B content at the cutting edge being at least 60% of the B content in an area at least 1 mm away from the cutting edge ridge toward the flank.